           (keyPressed [this e]
             (when (and @shortcuts/is-down?
                        (contains? consume-commands (.getKeyCode e)))
-              (.consume e)))))
-      (install-completer! completer))
+              (.consume e))))))
+    (when-let [completer (create-completer text-area extension)]
+      (install-completer! text-area completer))
     (JConsole. text-area)))
 
 (defn init-paredit!

  []
  (let [text-area (create-text-area)
        extension "clj"
        completer (create-completer text-area extension)
        consume-commands #{KeyEvent/VK_Z KeyEvent/VK_Y}]
    (doto text-area
      (.setSyntaxEditingStyle (get styles extension))

                :key-released
                (fn [e] (update-buttons! text-group text-area)))
      ; install completer
      (when completer
        (install-completer! text-area completer))
      ; enable/disable buttons while typing
      (.addDocumentListener (.getDocument text-area)
                            (reify DocumentListener
